Method: 1. Soak the black beans in slightly salted water for 8 hours or overnight. 2. Soak the corn kernels for 8 hours or overnight. 3. Drain the beans and rinse well. 4. Drain the corn and transfer to a large bowl. 5. Add the beans and all the other ingredients. 6. Mix well and keep it in the fridge until ready to serve. 8. This can be made 24 hours in advance.